Lipidome Analysis

In their main project on lipidome analysis, the Lipidomics group concentrates on the synthesis pathways in lipid metabolism and on the signals that control these pathways. For example, the group develops methods to determine when and how the lipid synthesis enzymes are activated and in which quantities they are present. Another important aspect in this project is the integration of quantitative proteome and lipidome data to gain a comprehensive overview of cellular processes. Moreover, the scientists are planning to investigate the effect of the metabolome on differentiation processes such as megakaryocyte differentiation or platelet activation. They also aim to elucidate regulatory mechanisms that might be employed, for instance, for the in vitro production of platelets in the pharmaceutical industry.

The group has established mesenchymal stem cells as a model system for this work. Among other things, these stem cells serve as forerunners for fat cells and for megakaryocytes, which in turn are forerunners of blood platelets. The process of differentiation is controlled by molecular switches; as soon as the decision is made that, for instance, a stem cell is to become a fat cell, massive conversion processes are started that also affect lipid composition. The differentiation of stem cells is therefore an ideal starting point for lipidomics, which in turn is of particular interest to biomedicine: for example, to research metabolic illnesses of the cardiovascular system and for basic research into obesity.

On the method level, the group uses two different approaches: shotgun lipidomics searches for the totality of all lipids in a sample. This approach would therefore seem best suited as a diagnostic method for comprehensive screenings. In contrast, if the objective is to determine whether a certain lipid is present in the sample (perhaps one that is responsible for obesity or cardiovascular illnesses), targeted lipidomics is more suitable.

As biological samples are often only available in tiny quantities, it is necessary to miniaturise the analysis structure. Even today, miniaturised methods of separation and ionisation, such as nano-electrospray and nano-RP-HPLC, enable the smallest quantities of samples to be analysed and quantities to be determined. This sensitivity is a particular benefit when certain metabolic disturbances or lipids harmful to health are to be identified, although these are only present in minute concentrations.